<title>节</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cp">#include</span> <span class="pl-cpf">&lt;algorithm&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span> <span class="pl-cpf">&lt;cstdio&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span> <span class="pl-cpf">&lt;cstring&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span> <span class="pl-cpf">&lt;queue&gt;</span><span class="pl-cp"></span>
<span class="pl-k">using</span> <span class="pl-k">namespace</span> <span class="pl-n">std</span><span class="pl-p">;</span>
<span class="pl-k">const</span> <span class="pl-kt">int</span> <span class="pl-n">N</span> <span class="pl-o">=</span> <span class="pl-mf">1e7</span> <span class="pl-o">+</span> <span class="pl-mi">10</span><span class="pl-p">,</span> <span class="pl-n">INF</span> <span class="pl-o">=</span> <span class="pl-mh">0x3f3f3f3f</span><span class="pl-p">;</span>
<span class="pl-k">struct</span> <span class="pl-n">Edge</span> <span class="pl-p">{</span>
    <span class="pl-kt">int</span> <span class="pl-n">to</span><span class="pl-p">,</span> <span class="pl-n">next</span><span class="pl-p">;</span>
<span class="pl-p">}</span> <span class="pl-n">e</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">E</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">];</span>
<span class="pl-kt">int</span> <span class="pl-n">len</span><span class="pl-p">,</span> <span class="pl-n">Head</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">tto</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">fro</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">p</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">t</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">];</span>
<span class="pl-kt">void</span> <span class="pl-nf">Ins</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">a</span><span class="pl-p">,</span> <span class="pl-kt">int</span> <span class="pl-n">b</span><span class="pl-p">)</span> <span class="pl-p">{</span>
    <span class="pl-n">e</span><span class="pl-p">[</span><span class="pl-o">++</span><span class="pl-n">len</span><span class="pl-p">].</span><span class="pl-n">to</span> <span class="pl-o">=</span> <span class="pl-n">b</span><span class="pl-p">;</span>
    <span class="pl-n">e</span><span class="pl-p">[</span><span class="pl-n">len</span><span class="pl-p">].</span><span class="pl-n">next</span> <span class="pl-o">=</span> <span class="pl-n">Head</span><span class="pl-p">[</span><span class="pl-n">a</span><span class="pl-p">];</span>
    <span class="pl-n">Head</span><span class="pl-p">[</span><span class="pl-n">a</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">len</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-n">l</span><span class="pl-p">,</span> <span class="pl-n">H</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">];</span>
<span class="pl-kt">void</span> <span class="pl-nf">Ins2</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">a</span><span class="pl-p">,</span> <span class="pl-kt">int</span> <span class="pl-n">b</span><span class="pl-p">)</span> <span class="pl-p">{</span>
    <span class="pl-n">E</span><span class="pl-p">[</span><span class="pl-o">++</span><span class="pl-n">l</span><span class="pl-p">].</span><span class="pl-n">to</span> <span class="pl-o">=</span> <span class="pl-n">b</span><span class="pl-p">;</span>
    <span class="pl-n">E</span><span class="pl-p">[</span><span class="pl-n">l</span><span class="pl-p">].</span><span class="pl-n">next</span> <span class="pl-o">=</span> <span class="pl-n">H</span><span class="pl-p">[</span><span class="pl-n">a</span><span class="pl-p">];</span>
    <span class="pl-n">H</span><span class="pl-p">[</span><span class="pl-n">a</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">l</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-n">low</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">dfn</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">stk</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">top</span><span class="pl-p">,</span> <span class="pl-n">num</span><span class="pl-p">,</span> <span class="pl-n">belong</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">],</span> <span class="pl-n">cnt</span><span class="pl-p">;</span>
<span class="pl-kt">long</span> <span class="pl-kt">long</span> <span class="pl-n">w</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">];</span>
<span class="pl-kt">void</span> <span class="pl-nf">tarjan</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">u</span><span class="pl-p">)</span> <span class="pl-p">{</span>
    <span class="pl-n">low</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">dfn</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-o">++</span><span class="pl-n">num</span><span class="pl-p">;</span>
    <span class="pl-n">stk</span><span class="pl-p">[</span><span class="pl-o">++</span><span class="pl-n">top</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">u</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">x</span> <span class="pl-o">=</span> <span class="pl-n">Head</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">];</span> <span class="pl-n">x</span><span class="pl-p">;</span> <span class="pl-n">x</span> <span class="pl-o">=</span> <span class="pl-n">e</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">].</span><span class="pl-n">next</span><span class="pl-p">)</span> <span class="pl-p">{</span>
        <span class="pl-kt">int</span> <span class="pl-n">v</span> <span class="pl-o">=</span> <span class="pl-n">e</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">].</span><span class="pl-n">to</span><span class="pl-p">;</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">dfn</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">])</span> <span class="pl-p">{</span>
            <span class="pl-n">tarjan</span><span class="pl-p">(</span><span class="pl-n">v</span><span class="pl-p">);</span>
            <span class="pl-n">low</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">min</span><span class="pl-p">(</span><span class="pl-n">low</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">],</span> <span class="pl-n">low</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">]);</span>
        <span class="pl-p">}</span> <span class="pl-k">else</span> <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">belong</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">])</span>
            <span class="pl-n">low</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">min</span><span class="pl-p">(</span><span class="pl-n">low</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">],</span> <span class="pl-n">dfn</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">]);</span>
    <span class="pl-p">}</span>
    <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">low</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">]</span> <span class="pl-o">==</span> <span class="pl-n">dfn</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">])</span> <span class="pl-p">{</span>
        <span class="pl-o">++</span><span class="pl-n">cnt</span><span class="pl-p">;</span>
        <span class="pl-k">while</span> <span class="pl-p">(</span><span class="pl-mi">1</span><span class="pl-p">)</span> <span class="pl-p">{</span>
            <span class="pl-kt">int</span> <span class="pl-n">x</span> <span class="pl-o">=</span> <span class="pl-n">stk</span><span class="pl-p">[</span><span class="pl-n">top</span><span class="pl-o">--</span><span class="pl-p">];</span>
            <span class="pl-n">belong</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">cnt</span><span class="pl-p">;</span>
            <span class="pl-n">w</span><span class="pl-p">[</span><span class="pl-n">cnt</span><span class="pl-p">]</span> <span class="pl-o">+=</span> <span class="pl-n">p</span><span class="pl-p">[</span><span class="pl-n">x</span><span class="pl-p">];</span>
            <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">x</span> <span class="pl-o">==</span> <span class="pl-n">u</span><span class="pl-p">)</span> <span class="pl-k">break</span><span class="pl-p">;</span>
        <span class="pl-p">}</span>
    <span class="pl-p">}</span>
<span class="pl-p">}</span>
<span class="pl-kt">bool</span> <span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">];</span>
<span class="pl-kt">long</span> <span class="pl-kt">long</span> <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">N</span><span class="pl-p">];</span>
<span class="pl-kt">void</span> <span class="pl-nf">spfa</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">s</span><span class="pl-p">,</span> <span class="pl-kt">int</span> <span class="pl-n">n</span><span class="pl-p">)</span> <span class="pl-p">{</span>
    <span class="pl-n">queue</span><span class="pl-o">&lt;</span><span class="pl-kt">int</span><span class="pl-o">&gt;</span> <span class="pl-n">q</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">n</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-o">-</span><span class="pl-n">INF</span><span class="pl-p">,</span> <span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
    <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">s</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">w</span><span class="pl-p">[</span><span class="pl-n">s</span><span class="pl-p">];</span>
    <span class="pl-n">q</span><span class="pl-p">.</span><span class="pl-n">push</span><span class="pl-p">(</span><span class="pl-n">s</span><span class="pl-p">);</span>
    <span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">s</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span>
    <span class="pl-k">while</span> <span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">q</span><span class="pl-p">.</span><span class="pl-n">empty</span><span class="pl-p">())</span> <span class="pl-p">{</span>
        <span class="pl-kt">int</span> <span class="pl-n">u</span> <span class="pl-o">=</span> <span class="pl-n">q</span><span class="pl-p">.</span><span class="pl-n">front</span><span class="pl-p">();</span>
        <span class="pl-n">q</span><span class="pl-p">.</span><span class="pl-n">pop</span><span class="pl-p">();</span>
        <span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
        <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-n">H</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">];</span> <span class="pl-n">i</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-n">E</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">].</span><span class="pl-n">next</span><span class="pl-p">)</span> <span class="pl-p">{</span>
            <span class="pl-kt">int</span> <span class="pl-n">v</span> <span class="pl-o">=</span> <span class="pl-n">E</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">].</span><span class="pl-n">to</span><span class="pl-p">;</span>
            <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">]</span> <span class="pl-o">&lt;</span> <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">]</span> <span class="pl-o">+</span> <span class="pl-n">w</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">])</span> <span class="pl-p">{</span>
                <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">u</span><span class="pl-p">]</span> <span class="pl-o">+</span> <span class="pl-n">w</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">];</span>
                <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">])</span> <span class="pl-p">{</span>
                    <span class="pl-n">q</span><span class="pl-p">.</span><span class="pl-n">push</span><span class="pl-p">(</span><span class="pl-n">v</span><span class="pl-p">);</span>
                    <span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">v</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span>
                <span class="pl-p">}</span>
            <span class="pl-p">}</span>
        <span class="pl-p">}</span>
    <span class="pl-p">}</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">()</span> <span class="pl-p">{</span>
    <span class="pl-n">freopen</span><span class="pl-p">(</span><span class="pl-s">&quot;jie.in&quot;</span><span class="pl-p">,</span> <span class="pl-s">&quot;r&quot;</span><span class="pl-p">,</span> <span class="pl-n">stdin</span><span class="pl-p">);</span>
    <span class="pl-n">freopen</span><span class="pl-p">(</span><span class="pl-s">&quot;jie.out&quot;</span><span class="pl-p">,</span> <span class="pl-s">&quot;w&quot;</span><span class="pl-p">,</span> <span class="pl-n">stdout</span><span class="pl-p">);</span>
    <span class="pl-kt">int</span> <span class="pl-n">n</span><span class="pl-p">,</span> <span class="pl-n">m</span><span class="pl-p">;</span>
    <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">n</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">m</span><span class="pl-p">);</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">m</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-p">{</span>
        <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">fro</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">],</span> <span class="pl-o">&amp;</span><span class="pl-n">tto</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]);</span>
        <span class="pl-n">Ins</span><span class="pl-p">(</span><span class="pl-n">fro</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">],</span> <span class="pl-n">tto</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]);</span>
    <span class="pl-p">}</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">n</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-p">{</span>
        <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">p</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]);</span>
    <span class="pl-p">}</span>
    <span class="pl-kt">int</span> <span class="pl-n">s</span><span class="pl-p">,</span> <span class="pl-n">P</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">n</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">dfn</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">])</span> <span class="pl-n">tarjan</span><span class="pl-p">(</span><span class="pl-n">i</span><span class="pl-p">);</span>
    <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">s</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">P</span><span class="pl-p">);</span>
    <span class="pl-n">s</span> <span class="pl-o">=</span> <span class="pl-n">belong</span><span class="pl-p">[</span><span class="pl-n">s</span><span class="pl-p">];</span>
    <span class="pl-kt">int</span> <span class="pl-n">pnum</span> <span class="pl-o">=</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">P</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-p">{</span>
        <span class="pl-kt">int</span> <span class="pl-n">a</span><span class="pl-p">;</span>
        <span class="pl-n">scanf</span><span class="pl-p">(</span><span class="pl-s">&quot;%d&quot;</span><span class="pl-p">,</span> <span class="pl-o">&amp;</span><span class="pl-n">a</span><span class="pl-p">);</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-o">!</span><span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">belong</span><span class="pl-p">[</span><span class="pl-n">a</span><span class="pl-p">]])</span> <span class="pl-p">{</span>
            <span class="pl-n">t</span><span class="pl-p">[</span><span class="pl-o">++</span><span class="pl-n">pnum</span><span class="pl-p">]</span> <span class="pl-o">=</span> <span class="pl-n">belong</span><span class="pl-p">[</span><span class="pl-n">a</span><span class="pl-p">];</span>
            <span class="pl-n">vis</span><span class="pl-p">[</span><span class="pl-n">belong</span><span class="pl-p">[</span><span class="pl-n">a</span><span class="pl-p">]]</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span>
        <span class="pl-p">}</span>
    <span class="pl-p">}</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">m</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-p">{</span>
        <span class="pl-kt">int</span> <span class="pl-n">u</span> <span class="pl-o">=</span> <span class="pl-n">belong</span><span class="pl-p">[</span><span class="pl-n">fro</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]],</span> <span class="pl-n">v</span> <span class="pl-o">=</span> <span class="pl-n">belong</span><span class="pl-p">[</span><span class="pl-n">tto</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]];</span>
        <span class="pl-k">if</span> <span class="pl-p">(</span><span class="pl-n">u</span> <span class="pl-o">!=</span> <span class="pl-n">v</span><span class="pl-p">)</span> <span class="pl-n">Ins2</span><span class="pl-p">(</span><span class="pl-n">u</span><span class="pl-p">,</span> <span class="pl-n">v</span><span class="pl-p">);</span>
    <span class="pl-p">}</span>
    <span class="pl-n">spfa</span><span class="pl-p">(</span><span class="pl-n">s</span><span class="pl-p">,</span> <span class="pl-n">cnt</span><span class="pl-p">);</span>
    <span class="pl-kt">long</span> <span class="pl-kt">long</span> <span class="pl-n">ans</span> <span class="pl-o">=</span> <span class="pl-o">-</span><span class="pl-mi">1</span><span class="pl-p">;</span>
    <span class="pl-k">for</span> <span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">i</span> <span class="pl-o">=</span> <span class="pl-mi">1</span><span class="pl-p">;</span> <span class="pl-n">i</span> <span class="pl-o">&lt;=</span> <span class="pl-n">pnum</span><span class="pl-p">;</span> <span class="pl-n">i</span><span class="pl-o">++</span><span class="pl-p">)</span> <span class="pl-p">{</span>
        <span class="pl-n">ans</span> <span class="pl-o">=</span> <span class="pl-n">max</span><span class="pl-p">(</span><span class="pl-n">ans</span><span class="pl-p">,</span> <span class="pl-n">dis</span><span class="pl-p">[</span><span class="pl-n">t</span><span class="pl-p">[</span><span class="pl-n">i</span><span class="pl-p">]]);</span>
    <span class="pl-p">}</span>
    <span class="pl-n">printf</span><span class="pl-p">(</span><span class="pl-s">&quot;%lld</span><span class="pl-se">\n</span><span class="pl-s">&quot;</span><span class="pl-p">,</span> <span class="pl-n">ans</span><span class="pl-p">);</span>
<span class="pl-p">}</span>
</cpde></pre></div>